Semiconductor Package C-Wing and Gull-Wing Lead Arrangement
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Solution Overview
Problem
The increasing trend in package miniaturization for molded semiconductor packages poses challenges in metal routing for contacting package leads, necessitating a more efficient arrangement of leads to facilitate smaller package bodies and reduce design constraints for carriers.
Innovation Solution
A semiconductor package design featuring a staggered arrangement of C-wing and gull-wing leads, where C-wing leads are bent inward and seated in a single groove at the bottom of the package body, and gull-wing leads extend outward, allowing for reduced metal routing complexity and miniaturization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If traditional lead arrangements are used in molded semiconductor packages, then the package structure is simple to manufacture, but the metal routing on the carrier becomes increasingly challenging with package miniaturization
Solution Approach 1:
The patent transitions from traditional planar lead arrangements to a three-dimensional configuration by bending leads into C-wings that extend vertically and horizontally in multiple directions. This dimensional change allows leads to be arranged in staggered rows with different orientations, reducing the footprint area required while maintaining electrical connectivity, thereby solving the metal routing challenge associated with package miniaturization
Solution Approach 2:
The C-wing leads are nested within grooves formed in the molded package body, with leads arranged in staggered rows where some leads are positioned at different heights and orientations. This nesting arrangement allows multiple leads to be compactly organized within a smaller space, reducing the overall package footprint while maintaining accessible contact points for carrier routing
2Productivity
If package miniaturization is pursued, then cost-per-package is reduced and process efficiency is enhanced, but the arrangement of leads becomes more challenging
Solution Approach 1:
The lead arrangement is segmented into distinct C-wing and gull-wing configurations, with leads divided into different subsets that are bent into specific shapes and positioned in staggered rows. This segmentation allows each lead subset to be optimized for specific routing requirements, simplifying the overall assembly process and enabling higher density packaging while maintaining manufacturing efficiency
Solution Approach 2:
The patent employs asymmetric lead configurations where C-wing leads are bent at specific angles and positioned in grooves, while gull-wing leads extend in different orientations. This asymmetric arrangement optimizes space utilization and simplifies carrier routing by creating distinct, non-overlapping lead paths, thereby enhancing process efficiency and enabling package miniaturization
Data Source
AI summary
A semiconductor package includes a semiconductor die embedded in a molded package body, leads electrically connected to the die and protruding from a side face of the molded package body, and a recess extending inward from the side face and into a bottom main face of the molded package body to forma single groove. The recess begins below a region of the side face from which the leads protrude, so that this region of the side face is flat and each of the leads exits the molded package body in the same plane. A first subset of the leads is bent inward towards the molded package body and seated in the single groove, to form a first row of leads configured for surface mounting. A second subset of the leads extends outward from the molded package body, to form a second row of leads configured for surface mounting.